Let's not leak details from src/shared and src/libsystemd into
src/basic, even though you can't actually do anything useful with
just forward declarations from src/shared.
The sd-forward.h header is put in src/libsystemd/sd-common as we
don't have a directory for shared internal headers for libsystemd
yet.
Let's also rename forward.h to basic-forward.h to keep things
self-explanatory.
Passing in the func, file and line information complicates the
interface. On top of that, it prevents forward declaring Hashmap in
strv.h, as we need to pass the macros everywhere that we allocate a
hashmap, which means we have to include the hashmap header everywhere
we have a function that allocates a hashmap instead of just having to
forward declare Hashmap.
Let's drop the file, func and line information from the debug information.
Instead, in the future we can add a description field to hashmaps like we
already have in various other structs to describe the purpose of the hashmap
which should be much more useful than having the file, line and function where
the hashmap was allocated.
Currently, hashmap_dump_sorted sorts by key and then returns the values
in order sorted by key. This commit adds another helper that does the
same but returns the sorted keys instead
This substantially reworks mempool_cleanup() so that it releases pools
with all freed tiles only, but keeps all pools with still-allocated
tiles around.
This is more correct, as the previous implementation just released all
pools regardless if anything was still used or not. This would make
valgrind shut up but would just hide memory leaks altogether. Moreover
if called during regular runtime of a program would result in bad memory
accesses all over.
Hence, let's add a proper implementation and only trim pools we really
know are empty.
This way we can safely call these functions later, when under memory
pressure, at any time.
I think this is nicer in general, and here in particular we have a lot
of code like:
static inline IteratedCache* hashmap_iterated_cache_new(Hashmap *h) {
return (IteratedCache*) _hashmap_iterated_cache_new(HASHMAP_BASE(h));
}
and it's visually appealing to use the same whitespace in the function
signature and the cast in the body of the function.
Also use double space before the tracking args at the end. Without
the comma this looks ugly, but it's a bit better with the double space.
At least it doesn't look like a variable with a type.
"internal" is a lot of characters. Let's take a leaf out of the Python's book
and simply use _ to mean private. Much less verbose, but the meaning is just as
clear, or even more.
Possibly fixes#15220. (There might be another leak. I'm still investigating.)
The leak would occur when the path cache was rebuilt. So in normal circumstances
it wouldn't be too bad, since usually the path cache is not rebuilt too often. But
the case in #15220, where new unit files are created in a loop and started, the leak
occurs once for each unit file:
$ for i in {1..300}; do cp ~/.config/systemd/user/test0001.service ~/.config/systemd/user/test$(printf %04d $i).service; systemctl --user start test$(printf %04d $i).service;done
So far, we'd use hashmap_free_free to free both keys and values along with
the hashmap. I think it's better to make this more encapsulated: in this variant
the way contents are freed can be decided when the hashmap is created, and
users of the hashmap can always use hashmap_free.
Found by inspecting results of running this small program:
int main(int argc, const char **argv) {
for (int i = 1; i < argc; i++) {
FILE *f;
char line[1024], prev[1024], *r;
int lineno;
prev[0] = '\0';
lineno = 1;
f = fopen(argv[i], "r");
if (!f)
exit(1);
do {
r = fgets(line, sizeof(line), f);
if (!r)
break;
if (strcmp(line, prev) == 0)
printf("%s:%d: error: dup %s", argv[i], lineno, line);
lineno++;
strcpy(prev, line);
} while (!feof(f));
fclose(f);
}
}
Let's first remove an item from the hashmap and only then destroy it.
This makes sure that destructor functions can mdoify the hashtables in
their own codee and we won't be confused by that.
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Adds the basics of the IteratedCache and constructor support for the
Hashmap and OrderedHashmap types.
iterated_cache_get() is responsible for synchronizing the cache with
the associated Hashmap and making it available to the caller at the
supplied result pointers. Since iterated_cache_get() may need to
allocate memory, it may fail, so callers must check the return value.
On success, pointer arrays containing pointers to the associated
Hashmap's keys and values, in as-iterated order, are returned in
res_keys and res_values, respectively. Either may be supplied as NULL
to inhibit caching of the keys or values, respectively.
Note that if the cached Hashmap hasn't changed since the previous call
to iterated_cache_get(), and it's not a call activating caching of the
values or keys, the cost is effectively zero as the resulting pointers
will simply refer to the previously returned arrays as-is.
A cleanup function has also been added, iterated_cache_free().
This only frees the IteratedCache container and related arrays. The
associated Hashmap, its keys, and values are not affected. Also note
that the associated Hashmap does not automatically free its associated
IteratedCache when freed.
One could, in theory, safely access the arrays returned by a
successful iterated_cache_get() call after its associated Hashmap has
been freed, including the referenced values and keys. Provided the
iterated_cache_get() was performed prior to the hashmap free, and that
the type of hashmap free performed didn't free keys and/or values as
well.
Daan De Meyer
Yu Watanabe
Matteo Croce
Lennart Poettering
Adrian Vovk
Zbigniew Jędrzejewski-Szmek
Susant Sahani
Topi Miettinen
Thomas Haller
Vito Caputo